Assembly for controlling the positioning of coke oven operating machines

ABSTRACT

At a coke oven of a coking plant, each operating machine is provided with a U-shaped detector unit equipped with infrared light gates. Each operating station of the coke oven is provided with a signal plate carrying positioning marker elements for fine tuning the positioning of the operating machine at the operating station and with identification marker elements for identifying the respective operating stations. Each infrared light gate includes an infrared light source and an infrared light sensor connected to an electronic evaluation circuit comprising a memory with a reading monitor for detecting and correlating the coded identification markers on the signal plates. The electronic evaluation circuit also includes an electronic position evaluation subcircuit which controls the drive of the respective coke oven operating machine to move the same at a reduced speed if a first positioning pulse is transmitted and to stop the operating machine upon the occurrence of a pair of positioning pulses as well as an identification signal identifying a desired operating station.

BACKGROUND OF THE INVENTION

This invention relates to an operating machine shiftably mounted on atrack alongside a coke oven at a coking plant. More particularly, thisinvention relates to an assembly at the coke oven for controlling thepositioning of the operating machine along the track.

A coking plant customarily includes a coke oven divided into severalchambers disposed seriatim. Each chamber is provided on its sides and atthe top with openings closable by respective chamber doors. Operatingmachines are shiftably mounted on tracks which run along both lateralsides and along the top side of the coke oven, the operating machinesbeing designed to charge and discharge the oven chambers after therespective chamber doors are opened. At the end of the coking process,the oven chambers are discharged by pushing the glowing coke out fromthe chambers onto a quenching carriage. In order to ensure smoothoperation of the coking plant, it is necessary to position the operatingmachines precisely at predetermined operating stations beside thechamber doors of the coke oven and, in addition, to position theoperating machines at the correct time.

German Laid-Open Application (Deutsche Offenlegungsschrift) No. 26 48049 discloses a method for controlling and monitoring the operation ofcoke oven operating machines, in which method a travel distancedetermination is made and which method attempts to attain fine tuningand synchronization in the positioning of the operating machinesalongside the coke oven. Code plates are disposed at the operatingstations of the individual coke oven operating machines, while readingdevices are attached to the operating machines for detecting informationcoded in the code plates. The code plates simultaneously serve to markthe centers of the respective oven chambers and to fine-tune thepositioning of the operating machines at the operating stations. Bycomparing the actual positions of the operating machines, as sensed bythe reading devices in cooperation with the code plates, with thedesired destinations in accordance with a current stage of a coke ovenoperating sequence, a central control unit generates signals forcontrolling the propulsion drives of the operating machines so that themachines are stopped at precise positions at the operating stations. Thecenters of the individual oven chambers are marked by magnets disposedon the code plates, the locations of the magnets being detected bycorresponding magnetic sensors on the operating machines. The readingdevices generate travel-direction reference values in the form ofpositive or negative voltages in accordance with the distances of theoperating machines from respective operating station centers and thedirections of motions of the operating machines with respect torespective operating stations.

A positioning method utilizing magnetic sensor and magnetic positionmarkers is disadvantageous owing to an inherently low positioningaccuracy resulting from the relative flatness, in the vicinity of a zeropoint, of the graph of the magnetic field strength as a function of thedirection of motion, the control voltages generated by Hall effectgenerators being concomitantly flattened.

An object of the present invention is to provide an improved assemblyfor controlling the positioning of coke oven operating machines alongrespective tracks.

A more particular object of the present invention is to provide such anassembly in which the positioning of the operating machines alongside acoke oven is accurate to millimeters.

Another particular object of the present invention is to provide such asassembly which is relatively insensitive to dust and heat.

SUMMARY OF THE INVENTION

An assembly for controlling the positioning of an operating machinealong a track at a coke oven comprises, in accordance with the presentinvention, at least one signal plate, a detector cooperating with theplate, a drive coupled to the operating machine for shifting the machinealong the track, and a control unit operatively connected to thedetector and to the drive for controlling the motion and positioning ofthe operating machine along the track in response to positioning signalsand identification signals received from the detector during a shiftingof the operating machine along the track. The detector includes aplurality of signal transmitters in the form of infrared light sourcesand a like plurality of signal receivers in the form of infrared lightsensors. The transmitters and receivers cooperate with the signal plateto generate the positioning signals indicating the arrival of theoperating machine at an operating station and the identification signalsindicating the location of the operating station (i.e., the identitythereof) with respect to the coke oven. The detector further includes aU-shaped carrier having a pair of opposed legs accommodating thetransmitters and receivers. One of the carrier and the signal plate ismounted to the operating machine, while the other is stationary withrespect to the coke oven so that the legs of the carrier are disposed onopposite sides of the signal plate upon arrival of the operating machineat the operating station. The control unit includes an electronicevaluation circuit and operates, during a shifting of the operatingmachine along the track, to reduce the velocity of the operating machineupon the transmission of a first positioning signal from the detector tothe control unit. The control unit stops the translation of theoperating machine along the track upon the transmission of a secondpositioning signal and of an identification signal coding a preselectedlocation alongside the coke oven. Alternatively, if the identificationsignal codes an unselected location alongside the coke oven, the controlunit induces an increase in the speed of the operating machine.

The signal plate advantageously includes a support body and at least twopositioning marker elements (such as small plates) and a plurality ofidentification marker elements all mounted to the support body. Thepositioning marker elements are spaced from one another along a firstline substantially parallel to the track, while the identificationmarker elements are aligned along a second line spaced from andsubstantially parallel to the first line. The marker elements are opaqueto a wavelength of infrared light generated by the transmitters anddetected by the sensors.

The transmitters, together with respective receivers, form amultiplicity of light gates, two of the light gates being disposed in afirst plane containing the first line and a plurality of the light gatesbeing disposed in a second plane containing the second line and orientedparallel to the first plane. The first positioning signal is generatedby the detector in response to an interruption of an infrared light beamof one light gate in the first plane by one of the positioning markerelements. The second positioning signal is generated in response to aninterruption of infrared beams of two light gates in the first plane bythe positioning marker elements. The identification signal is producedby light gates in the second plane upon generation of the secondpositioning signal and in accordance with interruptions of infraredlight beams of light gates in the second plane by the identificationmarker elements.

The electronic evaluation circuit preferably includes an addressable orread memory and a read-monitoring subcircuit which cooperate with oneanother for detecting and correlating the coded identification markerelements on the signal plate with the light gates of the detector toidentify the location of an operating station occupied by the operatingmachine at the time an identification signal is generated.

The electronic evaluation circuit further includes an electronicposition evaluation subcircuit operatively connected to the memory andthe read-monitoring subcircuit and to the drive for controlling thespeed and direction of motion of the operating machine along the track.

In accordance with another feature of the present invention, the signalplate is vertically oriented and the second line, defined by theidentification marker elements, is located above the first line, definedby the positioning marker elements. The positioning marker elements arepreferably attached to the support body at opposite ends thereof, whilethe identification marker elements are advantageously attached to thesupport body along an upper edge thereof so that the identificationmarker elements extend beyond that upper edge.

Pursuant to another feature of the present invention, at least one ofthe positioning marker elements is adjustably attached to the supportbody for altering the spacing of the positioning marker elements alongthe first line.

Pursuant to yet another feature of the present invention, the electronicread-monitoring circuit is operatively connected to the detector forcontinuously monitoring electrical output signals of the light gatesduring travel of the operating machine along the track between adjacentoperating stations.

An assembly for positioning an operating machine at a coke oven, inaccordance with the present invention, is simple and compact. Thesimplicity and compactness of the assembly arises in part from theutilization of identical components for identifying the stopping pointand for exactly positioning the operating machine at an operatingstation. The use of infrared radiation as the information carriereliminates the detrimental effects of dust and heat on the accuracy ofthe positioning system. Because the infrared light may be focussed byoptical components such as lenses and because light gates may be used,high response accuracy and high response speed may be achieved. The useof infrared transmitters and receivers permits, inter alia, theidentification of location without the interruption of the operatingmachine motion.

The disposition of positioning marker elements along one line atopposite ends of a support body and the disposition of identificationmarker elements along a top edge of the support body provides a verycompact arrangement of the positioning and identification marker on asingle plate, while permitting the detection of travel direction,position identification and fine tuning of the positioning process.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a block diagram of an assembly in accordance with the presentinvention for controlling the positioning of a coke oven operatingmachine, showing a U-shaped detector device, an identification andpositioning unit and a computer.

FIG. 2 is a partially diagrammatic perspective view of the U-shapeddetector of FIG. 1 and a signal plate insertable between the legs of thedetector.

FIG. 3 is a block diagram of the identification and positioning unit andthe U-shape detector of FIG. 1.

FIG. 4 is a flow chart diagram showing a sequence of operating stepsperformed by the computer of FIG. 1 in controlling a positioningassembly in accordance with the present invention.

DETAILED DESCRIPTION

As illustrated in FIG. 1, an assembly for controlling the positioning ofan operating machine alongside a coke oven of a coking plant comprisesan odometer unit 1 for determining the distance traveled by theoperating machine. Odometer unit 1 is connected at an input to a signalgenerator 2 exemplarily in the form of a magnetic pickup juxtaposed to awheel of the operating machine. An angular-step signal generator 3coupled to a drive motor of the coke oven operating machine is connectedto another input of odometer unit 1.

Odometer unit 1 is connected via a pair of output leads 61 and 62 to anidentification and positioning unit 4 and a reference-value transmitter5, respectively, for transmitting thereto a location signal formed inresponse to signals produced by signal generators 2 and 3.Reference-value transmitter 5 is connected to a motor control circuit 6in turn electrically coupled with drive motor 7 for controlling theoperation thereof.

Identification and positioning unit 4 is connected to a detector device9 which is preferably mounted on the operating machine and whichgenerates, in cooperation with signal plates fastened to the coke oven,positioning and indentification signals as described hereinafter. Theidentification and positioning unit is also connected at an output toreference-value transmitter 5. Odometer unit 1, identification andpositioning unit 4, reference-value transmitter 5 and motor controlcircuit 6 are all connected to a control computer 63 via a data bus 8.

In accordance with the signals received from generators 2 and 3,odometer unit 1 transmits a location signal to computer 63 via bus 8.Computer 63, having commenced operations in an initialization step 101(see FIG. 4) awaits the receipt of the location signal from odometerunit 1. Computer 63 scans input signals in a step 102, continuouslyinquiring at a decision junction 103 whether an operating machinelocation code has been received from odometer unit 1. Upon the receiptof the location code, computer 63 compares, in a step 104, the receivedlocation code with a desired location value. If the actual location isto one side, e.g., behind or to the left, of the desired location, asdiscovered by the computer at a decision junction 105, the computer 63transmits, in a step 106 a "forward" motion instruction toreference-value transmitter 5, this motion instruction corresponding tothe desired direction of motion of the coke oven operating machine.

In response to the motion instruction from computer 63, reference-valuetransmitter 5 sends to the control circuit 6 a command to switch on androtate the rotor of motor 7 in a direction determined by the "forward"motion instruction. Upon the execution of the command fromreference-value transmitter 5 by control circuit 6, the control circuittransmits, to computer 63 via data bus 8, a verification signalindicating that the execution of the command from reference-valuetransmitter 5 has taken place.

As illustrated in FIG. 4, computer 63 undertakes a scan 107 of inputsignals from the positioning assembly. Computer 63 inquires at adecision junction 108 whether a verfication signal has been receivedfrom control circuit 6. Upon reception of the verification signal fromcontrol circuit 6, computer 63 transmits a "forward" motion code tomodule 4 in a transmission step 109.

In addition to the "forward" motion code from computer 63,identification and positioning module 4 receives an enabling commandfrom odometer unit 1.

As illustrated in FIG. 2, detector 9 includes a U-shaped carrier member64 having a pair of parallel legs 65 and 66 defining a rectangularchannel 67 therebetween. In leg 65 carrier 64 is provided with amultiplicity of transmitters 11, 12 and 15 in the form of infrared lightsources. In the other leg 66 carrier 64 is provided with a likemultiplicity of receivers 13, 14 and 16 in the form of infrared lightsensors. U-shaped carrier 64 is advantageously attached to a coke ovenoperating machine so that channel 67 of the carrier faces downwardly andso that infrared light transmitters 11 and 12 and infrared light sensors13 and 14 are disposed in a common horizontal plane, while transmitters15 and sensors 16 are disposed in another horizontal plane spaced fromand located above the plane defined by transmltters 11 and 12 andsensors 13 and 14.

Transmitters 11 and 12 are each associated with a respective one of thesensors 13 and 14 to form therewith a pair of positioning light gates.Similarly, each transmitter 15 is paired with a respective sensor 16 tofrom a multiplicity of identification light gates.

Each operating station of a coke oven is provided, in accordance withthe present invention, with a stationary signal plate 10 exemplarilyillustrated in FIG. 2. Signal plate 10 includes a support body 17 in theform of a rectangular plate, a pair of positioning marker elements 18and 19 in form of two small square plates, and a multiplicity ofidentification marker elements 21 in the form of small rectangularplates. Positioning markers 18 and 19 are fastened to support body 17 atopposite ends thereof and along a line a₁ extending parallel to thetrack along which a coke oven operating machine is shiftable.Positioning markers 18 and 19 are disposed at essentially the samevertical position as the plane defined by transmitters 11 and 12 andsensors 13 and 14 (i.e., line a₁ is located in that plane). Similarly,identification markers 21 are attached to the top edge of support body17 along a line a₂ located at substantially the same vertical positionas transmitters 15 and sensors 16.

It is to be noted that both the number and the arrangement ofidentification markers elements 21 along the top edge of support body 17may be varied to form a unique identification code for an operatingstation. The signal plate illustrated in FIG. 2 has four identificationmarkers at one end and four identification markers at an opposite end ofsupport body 17 with a space separating the two groups of four markers,the space being sufficient to accommodate two further markers. Anothersignal plate (not illustrated) might have three identification markersfollowed by a space in turn followed by another three identificationmarkers followed by another space and a final identification markers. Asdescribed in detail hereinafter, detector 9 together with identificationand transmitting unit 7 (see FIGS. 1 and 3) and computer 63 co-functionto determine the pattern or configuration of the identification markers21 and thereby the identity of the associated operating station.

The light gates formed by transmitters 11 and 12 and sensors 13 and 14serve to enable the accurate positioning of an operating machine at anoven chamber (i.e., an operating station). Positioning marker elements18 and 19 preferably extend laterally somewhat beyond support body 17 ofmarking plate 10 and, being arranged in the same horizontal plane astransmitters 11 and sensors 13, at least partially interrupt, in thestopped position of the associated coke oven operating machine, theinfrared light beams projected from transmitters 11 and 12 towardssensors 13 and 14. At least one of positioning marker elements 18 and19, for example, marker 18, is adjustably fastened to support body 17 bymeans of a screw 20, for this purpose positioning marker 18 beingprovided with an elongated aperture 68 extending parallel to lines a₁and a₂. Screw 20 and aperture 68 enable an alteration of the spacingbetween positioning marker elements 18 and 19 so that it is equal to thespacing between the positioning light gates formed by transmitters 11and 12 and receivers 13 and 14.

Identification marker elements 21 extend upwardly beyond the upper edgeof support body 17 and, being disposed substantially in the samehorizontal plane as transmitters 15 and sensors 16, completely interruptthe infrared beams of respective light gates in that plane upon apositioning of the operating machine at an operating station such thatlegs 65 and 66 of carrier 64 flank the signal plate 10 associated withthat operating station. It is to be noted that marker elements 18, 19and 21 are necessarily opaque to infrared radiation.

FIG. 3 diagrammatically illustrates the electrical connections betweenthe transmitters and sensors of detector 9 and components ofidentification and positioning unit 4. Each transmitter and eachreceiver is linked to unit 4. Together with computer 63, identificationand positioning unit 4 serves to evaluate identification and positioningsignals transmitted by receivers 13, 14 and 16 of detector 9.

As illustrated in FIG. 3, detector 9 includes a lower infrared lightgate 22 and an upper infrared light gate 29. Light gate 22 includes atransmitter or infrared light source 23, a first optical lens 25, asecond optical lens 28, and a receiver or infrared light sensor 26.Transmitter 23 advantageously includes a light emitting diode 24, whilesensor 26 includes a photocell 27 sensitive to infrared radiation.Similarly, light gate 29 comprises a transmitter or infrared lightsource 30, a pair of optical lenses 32 and 35, and a receiver orinfrared light sensor 33, transmitter 30 including an infrared lightemitting diode 31 and sensor 33 including an infrared-sensitivephotocell 34. Transmitters 23 and 30 and receivers 26 and 33 of lightgates 22 and 29 are connected to identification and positioning module 4via a cable 36. Transmitter 23 represents either transmitter 11 or 12,while receiver 26 represents sensor 13 or 14. Analogously, transmitter30 and receiver 33 are equivalent to any one of transmitters 15 andsensors 16, respectively.

As shown in FIG. 3, identification and positioning unit 4 includes alogic module 37, a read or addressable memory 38 (preferably a read-onlymemory), a position indicator 39, a position evaluation module 40, aread-monitoring module 41, and a power supply 42.

Upon the transmission of a "forward" motion code to identification andpositioning module 4 by computer 63 in step 109 (FIG. 4), computer 63transmits, in a step 110, an enabling signal to logic module 37 via alead 43 (see FIG. 3). If computer 63 determines at decision junction 105that the actual location of an operating machine is not "behind" adesired location, computer 63 transmits a "reverse" motion instructionto reference-value transmitter 5 in a step 111. Computer 63 thereuponawaits the transmission from control circuit 6 of a verification signalindicating that motion of the operating machine in the "reverse"direction has been induced. The computer scans input signals in a step112 and inquires at a decision junction 113 whether the verificationsignal has arrived. Upon reception of the verification signal, computer63 transmits a "reverse" motion code to identification and positioningmodule 4 in a step 114 and then transmits an enabling signal to logicmodule 37 via lead 43 (step 110).

In response to the enabling signal from computer 63, logic module 37activates the positioning transmitters 11 and 12 (24 in FIG. 3) and thecorresponding receivers 13 and 14 (26 in FIG. 3) so that the diodes ofthe transmitters emit infrared light converted by the associated opticallenses 25 into parallel light beams which traverse channel 67 and arefocussed by the optical lenses 28 onto the receiver diodes 27 of therespective light gates.

In accordance with the motion instruction transmitted to reference-valuetransmitter 5 by computer 63, control circuit 6 moves the coke ovenoperating machine in a direction 69 (see FIG. 2) towards an operatingstation.

The light gate formed by transmitter 11 and sensor 13 first reachespositioning marker element 19 which cuts off a cross-section of theinfrared light beam, beginning at zero and proceeding through a maximumvalue in the center of the light gate up to complete interruption.Sensor 13 transmits a signal to position evaluation module 40 (FIG. 3)which feeds a start pulse to computer 63 via a lead 44. The start pulseis also transmitted to logic module 37 via a bidirectional multiple 70.Identification and positioning module 4 then tests whether the directionof motion of the operating machine corresponds to the desired direction,as communicated to module 4 by computer 63 in step 109 or 114. Computer63, also monitoring signals from position evaluation module 40 in a step115, compares the received signals with the desired direction code in astep 116. If computer 63 discovers at a decision junction 117 that theoperating machine is not moving in the desired direction, the computertransmits in a step 118 instructions to reference-value transmitter 5 tostop drive 7 of the operating machine and to reverse the direction ofrotor rotation of the drive for restarting operating machine in theopposite direction. Upon finding at decision junction 117 that theactual direction of motion of the coke oven operating machine coincideswith the desired direction, and upon the reception from positionevaluation module 40 via an output lead 46 of a "prepositioning pulse",computer 63 transmits in a step 119 an instruction to reference-valuetransmitter 5 to change the motion of the coke oven operating machine toan "inching" mode, i.e., to reduce the velocity of the machine.

With respect to the configuration illustrated in FIG. 2, the coke ovenoperating machine with detector 9 attached thereto moves in thedirection of arrow 69 at a reduced velocity during traversal of a traveldistance given by odometer unit 1 of the operating machine. Upon theinterruption by positioning marker elements 18 and 19 of the light gatesdefined by transmitters 11 and 12 and sensors 13 and 14, these sensorstransmit pulses to position evaluation module 40 (FIG. 3). Positionevaluation module 40 in turn informs logic module 37 of the pulses fromsensors 13 and 14, whereupon logic module 37 activates memory 38 foraddressing by signals from identification sensors 16.

It is to be noted that the second positioning signal, indicating thealignment of the identification light gates with the indentificationmarked elements, may consist of a single pulse from sensor 14 ratherthan concurrent pulses from both sensors 13 and 14.

Computer 63 awaits in a step 120 a station identification signal frommemory 38 in response to the activation states of sensors 16. It is tobe understood that if the operating machine had not been moving in thedesired direction, as indicated to identification and positioning module4 by computer 63 in step 109 or 114, computer 63 would have transmittedinstructions to reference-value transmitter 5 in step 118 to reverse thedirection of motion of the coke oven operating machine.

Upon the activation or enabling of memory 38 by logic module 37, outputleads of identification sensors 16 simultaneously address the memory andcause the reading out therefrom onto multiple 47 of a code identifyingthe particular operating station associated with the signal plate 10. Ifthe code read out from memory 38 does not coincide with the desiredstation code, as determined by computer 63 in a step 121 and an inquiry123, computer 63 transmits a signal, in a step 123, to logic module 37via lead 45 for terminating the inching mode of the operating machine.In response to that signal, logic module 37 resets position evaluationmodule 40, whereby the speed of the operating machine is increased toits normal level for traversing the distance between the operatingstation and another station adjacent thereto.

If the code read out from memory 38 coincides with the desired stationcode, as determined by computer 63 in step 121 and inquiry 122, computer63 awaits in a step 124 an identification verfication signal fromposition evaluation module 40. Module 40 transmits this verification or"in position" signal to computer 63 via a lead 48.

Upon the arrival of the two positioning light gates of detector 9 atpositioning marker elements 18 and 19, position-evaluation module 40feeds a stop signal to control reference-value transmitter 5 which inresponse de-energizes drive motor 7 of the coke oven operating machinevia control circuit 6. At the same time, in response to theidentification signals transmitted from sensors 16 of detector 9, memory38 reads out to position indicator 39 a code indicating the identity ofthe station at which the operating machine is located.

In a step 125, executed by computer 63 upon the reception thereby of anidentification verification signal from position evaluation module 40,computer 63 generates and stores a status code identifying the stationat which the coke oven operating machine is stopped. The computer checksthe status of each operating machine in a step 126. If all the operatingmachines have reached their intended positions, as determined by thecomputer art a decision junction 127, computer 63 generates signals forcontrolling the commencement of filling and discharging operations. Uponthe completion of the filling and discharging process, logic module 37receives from computer 63 an enabling and renewed direction inputsignal. As soon as one of the positioning light gates is free, positionevaluation module 40 transmits a "post-position pulse" to processcomputer 63 via lead 48. At the same time automatic read-monitoringmodule 41 is released and begins checking the identificationtransmitters 15 and sensors 16 continuously for errors in the event thatboth positioning light gates (11, 13 and 12, 14) are not covered. Uponthe occurrence of an error, position evaluation module 40 and memory 38are reset and the error is reported to computer 63. The computer thendecides whether shifting of the coke oven operating machine along itstrack is to be continued or temporarily arrested.

The identifying and positioning functions performed by detector 9 andmodule 4 in conjunction with computer 63, as described above withreference to FIG. 4, is repeated upon the reaching of anotherpositioning marker by one of the positioning light gates of detector 9.

The adjustable attachment of at least one of the positioning markerelements to support body 17 of signal plate 10 advantageously allows thesetting of the response sensitivity and the adjustment of the toleranceof the position markers to the desired value and also enables selectionof the hysteresis to optimize the deviation of the desired position as afunction of the travel direction, i.e., to select the most advantageousvalue as a function of the different parameters of the coke ovenoperating machine.

Although the invention has been described in terms of specificembodiments and applications, one of ordinary skill in the art, in lightof this teaching, can generate additional embodiments and modificationswithout departing from the spirit or exceeding the scope of the claimedinvention. Accordingly, it is to be understood that the drawings anddescriptions in this disclosure are proferred to facilitatecomprehension of the invention and should not be construed to limit thescope thereof.

What is claimed is:
 1. In combination with a coke oven in a cokingplant, said coke oven being provided with at least one operating machineshiftably mounted on a track alongside said coke oven, an assembly forcontrolling the positioning of said operating machine along said track,comprising:at least one signal plate; detector means, including aplurality of signal transmitters in the form of infrared light sourcesand a like plurality of associated signal receivers in the form ofinfrared light sensors, for cooperating with said signal plate togenerate positioning signals indicating the arrival of the shiftableoperating machine at an operating station along said track andidentification signals indicating the location of said operating stationwith respect to the coke oven, said detector means further including aU-shaped carrier having a pair of opposed legs accommodating saidtransmitters and receivers, one of said carrier and said signal platebeing mounted to said operating machine and the other of said carrierand said signal plate being stationary with respect to said coke oven sothat said legs of said carrier are disposed on opposite sides of saidsignal plate upon the arrival of said operating machine at saidoperating station; drive means operatively coupled to said operatingmachine for shifting same along said track; and control means includingan electronic evaluation circuit operatively connected to said detectormeans and to said drive means for controlling the motion and positioningof said operating machine along said track in response to saidpositioning signals and said identification signals so that, during ashifting of said operating machine, the velocity of said operatingmachine is reduced upon the transmission of a first positioning signalfrom said detector means to said control means, so that said operatingmachine is stopped upon the transmission of a second positioning signaland of an identification signal coding a preselected location alongsidesaid coke oven, and so that the speed of said operating machine isincreased upon the transmission of the second positioning signal and anidentification signal coding an unselected location alongside said cokeoven.
 2. The combination as defined in claim 1 wherein said signal plateincludes a support body and at least two positioning marker elements anda plurality of identification marker elements all mounted to saidsupport body, said positioning marker elements being spaced from oneanother along a first line substantially parallel to said track, saididentification marker elements being aligned along a second line spacedfrom and substantially parallel to said first line, said marker elementsbeing opaque to a wavelength of infrared light generated by saidtransmitters and detected by said receivers, said transmitters forming amultiplicity of light gates with respective ones of said receivers, twoof said light gates being disposed in a first plane containing saidfirst line and a plurality of said light gates being disposed in asecond plane containing said second line and oriented parallel to saidfirst plane, said first positioning signal being generated in responseto an interruption of an infrared light beam of one light gate in saidfirst plane by one of said positioning marker elements, said secondpositioning signal being generated in response to an interruption of aninfrared beam of another light gate in said first plane by saidpositioning marker elements, said identification signal being generatedby light gates in said second plane upon generation of said secondpositioning signal and in accordance with interruptions of infraredbeams of light gates in said second plane by said identification markerelements.
 3. The combination as defined in claim 2 wherein saidelectronic evaluation circuit includes decoding means including a readmemory operatively connected to said detector means for generating inresponse to said identification signal an electrical code signalidentifying the location of an operating station occupied by saidoperating machine upon generation of said identification signal.
 4. Thecombination as defined in claim 3 wherein said decoding means furtherincludes an electronic read-monitoring circuit for cooperating with saidread memory for detecting and correlating coded identification markerelements on said signal plate and light gates of said detector means. 5.The combination as defined in claim 4 wherein said electronic evaluationcircuit includes an electronic position evaluation circuit operativelyconnected to said decoding means and to said drive means for controllingthe speed and direction of motion of said operating machine along saidtrack.
 6. The combination defined in claim 2 wherein said signal plateis vertically oriented and said second line is located above said firstline, said positioning marker elements being attached to said supportbody at opposite ends thereof, said identification marker elements beingattached to said support body along an upper edge thereof so that saididentification marker elements extend beyond said upper edge.
 7. Thecombination as defined in claim 6 wherein at least one of saidpositioning marker elements is adjustably attached to said support bodywhereby the spacing of said positioning marker elements from one anotheralong said first line may be altered.
 8. The combination as defined inclaim 7 wherein said electronic read-monitoring circuit is operativelyconnected to said detector means for continuously monitoring electricaloutput signals of said light gates during travel of said operatingmachine along said track between adjacent operating stations.
 9. Incombination with a coke oven in a coking plant, said coke oven beingprovided with at least one operating machine shiftably mounted on atrack alongside said coke oven, an assembly for controlling thepositioning of said operating machine along said track, comprising:atleast one signal plate, said signal plate including a support body andat least two positioning marker elements and a plurality ofidentification marker elements all mounted to said support body, saidpositioning marker elements being spaced from one another along a firstline substantially parallel to said track, said identification markerelements being aligned along a second line spaced from and substantiallyparallel to said first line; detector means, including a plurality ofsignal transmitters in the form of infrared light sources and a likeplurality of associated signal receivers in the form of infrared lightsensors, for cooperating with said signal plate to generate positioningsignals indicating the arrival of the shiftable operating machine at anoperating station along said track and identification signals indicatingthe location of said operating station with respect to the coke oven,said detector means further including a U-shaped carrier having a pairof opposed legs accommodating said transmitters and receivers, one ofsaid carrier and said signal plate being mounted to said operatingmachine and the other of said carrier and said signal plate beingstationary with respect to said coke oven so that said legs of saidcarrier are disposed on opposite sides of said signal plate upon thearrival of said operating machine at said operating station, said markerelements being opaque to a wavelength of infrared light generated bysaid transmitters and detected by said receivers, said transmittersforming a multiplicity of light gates with respective ones of saidreceivers, two of said light gates being disposed in a first planecontaining said first line and a plurality of said light gates beingdisposed in a second plane containing said second line and orientedparallel to said first plane, said first positioning signal beinggenerated in response to an interruption of an infrared light beam ofone light gate in said first plane by one of said positioning markerelements, said second positioning signal being generated in response toan interruption of an infrared beam of another light gate in said firstplane by said positioning marker elements, said identification signalbeing generated by light gates in said second plane upon generation ofsaid second positioning signal and in accordance with interruptions ofinfrared beams of light gates in said second plane by saididentification marker elements; drive means operatively coupled to saidoperating machine for shifting same along said track; and control meansincluding an electronic evaluation circuit operatively connected to saiddetector means and to said drive means for controlling the motion andpositioning of said operating machine along said track in response tosaid positioning signals and said identification signals so that, duringa shifting of said operating machine, the velocity of said operatingmachine is reduced upon the transmission of a first positioning signalfrom said detector means to said control means, so that said operatingmachine is stopped upon the transmission of a second positioning signaland of an identification signal coding a preselected location alongsidesaid coke oven, and so that the speed of said operating machine isincreased upon the transmission of the second positioning signal and anidentification signal coding an unselected location alongside said cokeoven, said electronic evaluation circuit including decoding means with aread memory operatively connected to said detector means and anelectronic read-monitoring circuit for detecting and correlating codedidentification marker elements on said signal plate and light gates ofsaid detector means, said electronic evaluation circuit furtherincluding an electronic position evaluation circuit operativelyconnected to said decoding means and to said drive means for controllingthe speed and direction of motion of said operating machine along saidtrack.
 10. The combination as defined in claim 9 wherein said signalplate is vertically oriented and said second line is located above saidfirst line, said positioning marker elements being attached to saidsupport body at opposite ends thereof, said identification markerelements being attached to said support body along an upper edge thereofso that said identification marker elements extend beyond said upperedge.
 11. The combination as defined in claim 10 wherein at least one ofsaid positioning marker elements is adjustably attached to said supportbody whereby the spacing of said positioning marker elements from oneanother along said first line may be altered.
 12. The combination asdefined in claim 11 wherein said electronic read-monitoring circuit isoperatively connected to said detector means for continuously monitoringelectrical output signals of said light gates during travel of saidoperating machine along said track between adjacent operating stations.